Abrasive roll



1 Sept. 7, 1948. A. E. HAMILTON ABRAS IVE ROLL Filed March 19, 1946 N Y. 0 E NU N w! P m m WH. T E .SH D M. u 4.

will. will, '"f'f l l l] 'll/lll Patented Sept. 7, 1948 UNITED STATES PATENT OFFICE 2 Claims.

My invention relates to rolls for use in the surfacing of strip or sheet material of steel, wood, etc., and more particularly to rolls of the type having an abrasive strip or sleeve that surrounds a pneumatic drum and in which air under pressure is maintained to provide a desired resistance to grinding pressures.

In rolls of this type. it has been -found advantageous to use abrasive-containing strips wrapped around the pneumatic drum, usually in a helical direction, the drum being then infiated to a working pressure. While the abrasive strips can readily be wrapped on the drum, the adequate fastening of the ends of the strips to securely hold them in position under working stresses has heretofore required the use of clamping devices that are cumbersome and cannot be quickly applied and removed.

One object of my invention is to provide means for fastening the ends of abrasive strips on a pneumatic drum in a simpler manner than various means heretofore employed, and which will permit easy and quick installation and replacen ment of abrasive strips on the drums.

Another object of my invention is to provide a fastening arrangement for the ends of the abrasive strips, whereby the holding or anchoring force for the strip ends is obtained from the pneumatic pressure within the drum.

Figure 1 is a face view partly in section of an abrasive roll embodying one form of my invcntion, and Fig. 2 is a sectional View of a portion thereof, on an enlarged scale.

In the drawing I show a roll having a cylindrical metal hub portion 3 mounted on a shaft 4 and `carrying a pneumatic drum 5 which may suitably be of rubber and in which air is maintained under pressure. The air may suitably be supplied through pressure-supply and regulating devices such as that shown in my Patent 2,368,760. Abrasive strips 6 are wrapped around the drum While there is little or no air pressure therein and suitably may be of heavy paper or cloth having abrasive grains adhesively connected to their exposed faces.

Where the strips 6 are of relatively narrow width, two or more strips wrapped in parallelism will be required to cover the drum, as here shown, but if a wider strip is employed and the helical pitch is not too great, a single strip may be sufficient to cover the drum, in which case the strip ends are preferably tapered to a reduced width. The abrasive strips have their ends folded inwardly as shown at 1 and are tucked behind a preceding strip-turn, this insertion being made between the periphery of the hub 3 and the inner surface of the preceding strip-turn. Upon admission of air pressure to the drum 5, the peripheral drum wall will be swelled outwardly to place the strip-turns under tension and to grip the tucked in ends at 1 between the drum wal1 and the overlying strip-turn, thereby holding such ends rmly in place. Theresistance to displacement of the strip is adequate, because the swelling of the drum under its internal working pressure will tighten the helical turns and cause the tucked-in ends to be gripped against the drum, and the granules on the tucked-in portions 'l of the strips will not slide readily on the peripheral surface of the drum.

I claim as my invention:

1. An abrasive roll comprising a hub portion, a pneumatic drum normally closely tting the peripheral surface of the hub, and an abrasive strip surrounding the drum and wound in a helical direction, the end portions of the strip at each end of the drum being folded backwardly between a preceding strip-turn and the periphery of the drum, whereby, upon ination of the drum, such turned-back ends will be gripped against the periphery of the drum.

2. An abrasive roll comprising a hub portion, a pneumatic drum normally closely tting the peripheral surface of the hub, abrasive strips wound on the drum in a helical direction portions of the endmost turns of the strips at each end of the drum being tucked behind preceding turns and against the periphery of the drum, whereby, upon inflation of the drum, the tucked-in portions will be gripped.

ALFRED E. HAMILTON.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,108,193 Brackett Feb. 15, 1938 2,323,962 Ames July 13, 1943 2,368,760 Hamilton Feb. 6, 1945 

